Guide yoke



S. S. BRAME Feb. 28, 1956 GUIDE YOKE 2 Sheets-Sheet 1 Filed April 17, 1953 W l lllll 34 IIH Tr I Vmm I Sam 5. Emma INVENTOR.

S. S; BRAME Feb. 28, 1956 GUIDE YOKE 2 Sheets-Sheet 2 Filed April 17, 1953 Fig. 5

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United States Patent O GUIDE YOKE Sam S. Brame, Waco, Tex. Application April 17, 1953, Serial No. 349,493

1 Claim. c1. 308-6) This invention relates generally to attachments for cutting tools and pertains more particularly to a guide yoke for constraining the movement of a cutting tool to a predetermined path of movement.

A primary object of this invention is to provide a guide attachment for cutting tools which is of simple and economical construction and yet which is fully effective to produce the desired results. I

Another object of this invention is to provide an improved guide assembly for cutting tools which includes a novel type of eccentrically adjustable roller for maintaining the proper engagement of the guide assembly with the trackway with which it is associated.

Another object of this invention is to provide a guide yoke for powered cutting tools in which the roll assemblies are selectively movable into a plurality of transverse positions with respect to the yoke for maintaining the proper engagement of the rollers with the guide track.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout and in which:

Figure l is a vertical elevation of the power cutting tool with the novel attachment secured thereto;

Figure 2 is a bottom plan view of the assembly shown in Figure l but showing the guide track in dotted lines;

Figure 3 is a vertical section taken substantially along the plane of section line 33 of Figure 1 showing details of the guide yoke.

Figure 4 is a bottom plan view of the yoke mechanism having its rollers disposed in position for engagement within a channel guide;

Figure 5 is a transverse vertical section taken substantially along the plane of section line 55 of Figure 4 showing the manner of engagement of the rollers in the channel;

Figure 6 is a diagrammatic view showing the guide yoke travelling along a serpentine path; and

Figure 7 is a bottom plan view of a modified form of the guide yoke assembly showing the trackway in dotted lines.

Referring now more particularly to Figure 1, reference numeral 10 indicates generally the portable powered cutting tool which is provided at its forward end with an inclined table portion 12 which carries a stationary cutting blade 14. The reciprocable cutting blade 16 is carried by the head 18 of the machine or tool and is movable toward and away from the stationary blade to perform cutting operations on material engaged between the blades. The construction shown is of the type generally used in sheet metal cutting operations and since the operation of these tools is well known, it will suflice to say that a sheet of metal is engaged between the cutting blades of the tool and the power is applied thereto which progressively feeds the tool along the work to perform a cutting or shearing action on the metal, the tool being manually guided by the operator.

It will be manifest that .the accuracy of a cut performed in the above manner depends largely upon the skill of the operator and with a highly trained mechanic minor inaccuracies are bound to occur which, in some instances, cannot be tolerated.

This invention therefore contemplates the use of a platelike yoke member 20 which is suitably secured to the undersurface of the member 12 and constitutes a supporting bed for the machine or tool. At opposite, ends of the yoke are provided the laterally projecting ears 22 disposed at each side of the yoke and it will be readily seen that each of the ears is provided with an aperture 24 being countersunk at its upper extent to receive the head 26 of a suitable fastening element which extends, through the aperture and below the undersurface 28 thereof. A depending boss 30 is disposed concentrically of each of the apertures on the lower surface of the yoke and it will be seen that the hub or central portion 32 of the roller 34 are engaged thereagainst under the action of the fastening element. The threaded aperture 36 within which the lower end of the fastening elements are threadedly engaged are, disposed eccentrically 'with respect to the hub portion 32, such portion being of cylindrical configuration and forming on its outer surface the raceway 38 for receiving the ball bearing 40. An annular roller ring 42 is disposed concentrically of the hub portion 32 and its inner surface is provided with the raceway 44 for receiving the previously mentioned balls 40 so that the ring is free to turn about the cylindrical hub 32, as will be readily apparent.

In addition to the previously mentioned transversely spaced ear apertures 24, each end of the yoke assembly is provided with a substantially central opening or aperture 46 which is identical in construction and purpose to the ear apertures 24.

In operation of the roller type guide assembly, with reference to Figures 1 and 2, it will be seen that the yoke plate is disposed upon the guide or track 48 which includes the bed plate portion 50 and the upstanding rail 52, the rollers 34 of the yoke assembly being disposed in straddling relation to the rail 52. In order to adjust the rollers with respect to the yoke and the rail to secure a proper and desired engagement between the rollers and the rail to prevent lateral shifting of the cutting tool, the fastening elements may be loosened and the hub portion 32 rotated so that there eccentricity moves the rollers inwardly or outwardly as desired. For operation with the rail type of guide track, the rollers at opposite ends of the yoke are disposed in the ear apertures, the central aperture 46 being inoperative.

When desired to utilize the guide yoke in conjunction with the channel type trackway 54, one of the roller assemblies 34 is movedlaterally toward the other at each end of the yoke so that the central aperture 46 is utilized to carry the second roller. The rollers are then individually adjusted to maintain and procure the proper engagement with the upstanding rail members 56 and 58 which form a channel way therebetween along which the tool is to be guided for a desired predetermined path of cut.

Referring to Figure 6, one predetermined path of movement of cut that might be desired is shown by the serpentine winding of the guide rail 60, the guide yoke 20 being shown in progressive positions therealong.

Referring now more particularly to Figure 7, it will be seen that a modified type of guiding assembly maybe utilized in conjunction with the yoke 20, this guiding assembly taking the form of elongated bars 60 and 62 which may be secured to the ear apertures by means of the previously mentioned fastening elements in the position shown to operate in straddling relation to a centrally disposed track or rail. It will be noted that the apertures in the bars are laterally ofiset with respect to a center line of the bar so that the same may be reversed to present difierent efiective over-all straddling with various types of guide rails. Preferably, the end of the bars are bevelled as at 64 and 66, respectively, for ease of entrance of the bars upon the guide rails or into the guide channel when the bars are so disposed to cooperate therewith. In the latter respect, it will be noted that it is preferred that the distance between the rails forming the channel is such that both of the bars are reversed from their position shown in Figure 7 so that their bevelled ends are disposed at opposite sides of the yoke allowing easy entrance into such channel.

The yoke may be either formed separately for use with existing tools or may be formed integrally with the base of the tool. Also, the yoke is not necessarily limited to the metal cutting tool of the type illustrated.

From the foregoing, the construction and operation of the device will be readily understood and further explanation is believed to be unnecessary. However, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling Within the scope of the appended claim.

What is claimed as new is as follows:

A guide yoke for power tools comprising an elongated base adapted to be secured to a tool, a pair of rollers journaled on the undersurface of said base about axes perpendicular thereto, each of said rollers including a circular center portion and an annular roller ring disposed concentrically of and journaled on said center portion, said center portions being provided with eccentrically disposed threaded apertures, and a pair of fastening elements projecting through said base and received in said threaded apertures, the undersurface of said base being provided with a pair of annular bosses through which said fasteners extend and clamp said center portions to said bosses in spaced relation to said base and in selected spaced apart positions relative to each other.

References Cited in the file of this patent UNITED STATES PATENTS 1,410,972 Wagner Mar. 28, 1922 1,646,129 Wagner Oct. 18, 1927 1,793,208 Biggert Feb. 17, 1931 1,794,836 'De Walt Mar. 3, 1931 2,309,298 7 Bickel Jan. 26, 1943 2,430,136 Nilsson et a1. Nov. 4, 1947 2,622,939 Ljunggren Dec. 23, 1952 

